Laser structure based on a fiber ring and peanut-shaped whisper gallery mode microresonator

This study introduces a novel optical fiber laser system integrating a peanut-shaped whispering gallery mode microresonator (PSM) and an Erbium-doped fiber ring laser. We investigate the influence of the position of the light coupling fibre taper on the performance of the proposed laser to achieve lasing wavelength tunability, mode-switching, and multi-wavelength operation. Our findings demonstrate that varying the geometric dimensions of the PSM and the coupling taper position directly influences lasing performance, allowing precise control over emission wavelengths and mode characteristics. The unique peanut shape of the microresonator enables distinct mode solutions, which enhances the stability and tunability of the laser output. This research underscores the potential of geometrically tailored PSMs to advance the development of photonic devices, offering significant implications for next-generation optical systems in telecommunications and beyond. The results highlight the importance of microresonator geometry in optimizing the performance of fiber lasers.